1. Field of the Invention
The present invention relates generally to the fabrication of magnetic heads for hard disk drives, and more particularly to the fabrication of a narrow P2 pole tip and a fine pitch induction coil using a single image transfer step.
2. Description of the Prior Art
Efforts to increase the performance characteristics of hard disk drives have focused on increasing the areal data storage density of the magnetic hard disks and increasing the data writing rate of magnetic heads in writing data to the hard disks. As will be understood from reading this detailed description, the present invention advantageously affects both of these hard disk performance characteristics.
One way to increase the areal data storage density is to decrease the width of the data tracks upon the hard disk media. Narrower data tracks allow for more tracks per inch (TPI) to be written on a disk, thereby increasing the areal data storage density of the disk. The well recognized method for decreasing the width of the data tracks is to decrease the width of the P2 pole tip of the magnetic head, because the width of the P2 pole tip generally determines the width of the data track that is written by the magnetic head. Prior art photolithographic techniques for fabricating P2 pole tips are currently reaching the limits of process accuracy, in that it is difficult to accurately and reliably fabricate high aspect ratio P2 pole tip trenches utilizing photolithographic techniques. Recently, high aspect ratio P2 pole tip trenches have been fabricated utilizing reactive ion etch (RIE) techniques, which have produced good results where the P2 pole tip is subsequently electroplated into the RIE created trench. The present invention is an improvement in the RIE P2 pole tip fabrication process for the fabrication of magnetic heads, as is discussed in detail below.
To improve the magnetic head data writing rate, prior art magnetic heads have been fabricated with higher aspect ratio induction coils. Such high aspect ratio induction coils allow for the individual induction coil turns to be spaced closer together, creating a fine pitch induction coil. Where a fine pitch induction coil is fabricated, the P2 pole yoke can be shortened, thus creating a similarly shortened magnetic flux circuit through the P1 and P2 poles, such that the data writing rate of the magnetic head is increased.
The present invention advantageously utilizes one dielectric layer, one RIE mask and image transfer step, and one RIE step to create both a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil. In so doing, fabrication problems associated with separate RIE processes for creating a P2 pole tip and for creating a fine pitch induction coil are avoided, and the fabrication of an improved magnetic head is simplified.
The magnetic head of the present invention includes a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil. Electroplating trenches for the P2 pole tip and the induction coil are fabricated in a single RIE process step, and the P2 pole tip and the induction coil are thereafter separately plated up into their respective trenches to complete the fabrication of these structures.
Briefly, following the fabrication of a P1 pole and the deposition of an insulation layer thereon, a patterned P2 pole tip seed layer is deposited. Significantly, the pole tip seed layer is not deposited beneath the induction coil area of the magnetic head. A dielectric layer is next deposited and a patterned RIE etching mask is fabricated upon the dielectric layer. The etching mask pattern includes both a P2 pole tip trench opening and an induction coil trench opening. Thereafter, in a single RIE etching step, the P2 pole tip trench is etched through the dielectric material down to the seed layer, and the induction coil trench is etched through the dielectric material down to the insulation layer. The P2 pole tip is then electroplated up into its trench, and no electroplating occurs within the induction coil trench because no seed layer has been yet deposited therein. Following the electroplating of the P2 pole tip, an induction coil seed layer is deposited upon the wafer surface and specifically down into the induction coil trench. Thereafter, the induction coil is electroplated up into the induction coil trench. A chemical mechanical polishing (CMP) step is next conducted to remove the excess induction coil material and the RIE etching mask. Thereafter, a patterned insulation layer is deposited upon the induction coil, which is followed by the fabrication of a P2 pole yoke thereupon. Further fabrication steps as are known to those skilled in the art are thereafter accomplished to complete the magnetic head of the present invention.
It is an advantage of the magnetic head of the present invention that it includes a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil.
It is another advantage of the magnetic head of the present invention that the P2 pole tip and the induction coil are fabricated utilizing a single RIE etching mask.
It is a further advantage of the magnetic head of the present invention that it includes a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil that are fabricated in a single dielectric layer.
It is an advantage of the hard disk drive of the present invention that it has an increased areal data storage density and an increased data writing rate.
It is another advantage of the hard disk drive of the present invention that it includes a magnetic head of the present invention having a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil.
It is another advantage of the hard disk drive of the present invention that it includes a magnetic head of the present invention wherein the P2 pole tip and the induction coil are fabricated utilizing a single RIE etching mask.
It is a further advantage of the hard disk drive of the present invention that it includes a magnetic head of the present invention that includes a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil that are fabricated in a single dielectric layer.
It is an advantage of the fabrication method of the present invention that a narrow, high aspect ratio P2 pole tip and a high aspect ratio, fine pitch induction coil are fabricated within a single dielectric material layer.
It is another advantage of the method for fabricating a magnetic head of the present invention that the P2 pole tip trench and the induction coil trench are fabricated in a single RIE etching step.
These and other features and advantages of the present invention will no doubt become apparent to those skilled in the art upon reading the following detailed description which makes reference to the several figures of the drawings.